Evaluation of Border Leicester × Romney (BR), Poll Dorset × BR, and Suffolk × BR ewes for out-of-season lambing

Abstract

Abstract Three different year groups of Border Leicester × Romney (BR), Poll Dorset × BR (PBR), and Suffolk × BR (SBR) ewes were evaluated for yearling liveweight and greasy fleece weight, and for their 2– and 3–year-old lambing performance under both June– and August-lambing policies. Mating of the June-lambing ewes was induced using progesterone treatment and high ram:ewe ratios. Suffolk × BR hoggets were significantly (P < 0.01) heavier than PBR and BR ewe hoggets in May, October, and January (at about 16 months of age). Border Leicester × Romney hoggets produced significantly (P < 0.01) more greasy wool at the yearling shearing than PBR or SBR hoggets. Lambing policy did not influence the proportion of ewes lambing but there were more (P < 0.05) multiple births in August-lambing ewes. Birth weights and weaning weights of June-born lambs were lower (P < 0.001) than those of their August-born counterparts. Weight of lamb weaned per ewe joined was 22.1 kg for June-lambing ewes and 24.3 kg for August-lamb...